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Discussion Starter #1
Would it be possible to pull a trailer from a ball installed on the draw bar of a 3 point hitch ? I know that towing implements exist (10,000 lbs. tongue weight) but I was wondering about a hitch ball on the center hole of the. I could also hook chains on the other hole to secure the trailer. What about the drawbar rolling on it's mounts ? What's the max weight that can be put on a unimog 3-point hitch like mine (cat 5 ?)
 

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I would not tow a trailer that uses a ball hitch on public roads with the drawbar between the 3 point hitch arms. I have done it before around the farm at low speeds, but the rotation of the bar under acceleration and braking put too much force on the ball and the pivots, and I believe that it would be very easy to either break something or pop the ball out of the trailer coupling if there was some sort of emergency stopping situation. you might be alright, but I wouldn't chance it, it would be bad enough to loose the trailer, but another thing entirely to hurt someone in the process. I personally would build a frame mounted hitch rather than hooking to the three point hitch for one reason... the U.S. DOT (department of transportation) officers. A towing hitch like the one you pictured would work well, but I am sure it is not DOT rated, and the 3 point hitch does not have a mechanical position lock to keep it from going down, and the rules say that any movable hitch must be able to be mechanically locked into position on a road going vehicle. I know that the mog 3 point hitch has a hydraulic lock valve, but it won't cut it with a DOT officer and you will get sidelined or have to leave the trailer if you get stopped for an infraction (or even if you just get stopped because the officer wants to see what the hell you are driving). You probably wouldn't have an issue, but then again the mog does draw a lot of attention. Sorry to rain on your day, but I would hate for something to happen and you end up with fines, ect, ect.

Cheers,
Ben
 

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Discussion Starter #3
I would not tow a trailer that uses a ball hitch on public roads with the drawbar between the 3 point hitch arms. I have done it before around the farm at low speeds, but the rotation of the bar under acceleration and braking put too much force on the ball and the pivots, and I believe that it would be very easy to either break something or pop the ball out of the trailer coupling if there was some sort of emergency stopping situation. you might be alright, but I wouldn't chance it, it would be bad enough to loose the trailer, but another thing entirely to hurt someone in the process. I personally would build a frame mounted hitch rather than hooking to the three point hitch for one reason... the U.S. DOT (department of transportation) officers. A towing hitch like the one you pictured would work well, but I am sure it is not DOT rated, and the 3 point hitch does not have a mechanical position lock to keep it from going down, and the rules say that any movable hitch must be able to be mechanically locked into position on a road going vehicle. I know that the mog 3 point hitch has a hydraulic lock valve, but it won't cut it with a DOT officer and you will get sidelined or have to leave the trailer if you get stopped for an infraction (or even if you just get stopped because the officer wants to see what the hell you are driving). You probably wouldn't have an issue, but then again the mog does draw a lot of attention. Sorry to rain on your day, but I would hate for something to happen and you end up with fines, ect, ect.

Cheers,
Ben

Let's say I get an implement fabbed-up like the yellow one on the pictures, what is needed for it to be considered DOT ?
 

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I agree with Ben, a frame mounted hitch is what I would do.

Here are some photos of balls on drawbars, but they are in Europe. We tend to put heavier loads on ball hitches than they do. When hauling heavier loads , the Rockinger type hitch gets the assignment over there.
 

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Discussion Starter #5
The best thing would be some kind of adaptor that could allow using a normal gooseneck trailer on my rocklinger hitch.

It seems dificult to find trailers in north america that could be hooked-up at a rocklinger-height.
 

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Towing balls over hear (50mm) as you would find on small cars, Land rovers/4x4 & trucks are for trailers <3500kg gross weight with a tong load of <200kg though most work in the range of >50kg (small car) < 150kg (land rover type 4x4) tong load.

We also have 80mm & 110mm balls, though the automatic pin type is most common (Rockinger/etc type)

Cat2 implement drawbar can take a tong weight (nose weight) of 600kg (cat3 = 900kg), the lift-arms them self’s can lift >4000kg at the ball-ends.

Note implement drawbar:
You cannot use a centrally mounted ball unless you stabilise the implement drawbar from rotating around its axis & also realise that any mechanism that fixes from the implement drawbar to the lift-arms must also be able to move freely allowing the lift-arms to move up and down in opposite directions to each other.

This is because the cross-shaft & lifting spindles are fixed to the chassis & the lift-arms have one end fixed to the rear axel & the other to the relevant lifting spindle, thus any rotation in the axel vs. lifting spindles vs. the chassis results in the lift-arm implement ball moving up or down countering the axel movement &/or chassis role. ;)
 

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You are right about trailer heights, Unimog frame height not common.
For light to moderate loads on the drawbar using a ball I put pins that protruded from the front of the bar into the arms on both sides in corresponding drilled holes. For off road use only, probably not DOT. I believe a stock item on the lighter Unimog three point. These pins prevent the bar from rotating. On a 406 towed with that setup, never had a problem.
But of course, if you can use that Rockinger it is the best thing to tow with. Here is my 'ol 406 pulling the rear half of a Honeywagon with a Rockinger...somewhere in the neighborhood of 25,000 lbs.
 

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Hi Mogish,
Here is what I use around the farm or between fields if the load isn't too big


For pulling heavier loads (often 12ton dump trailer) I have a swinging drawbar made by Uniquip - it hangs on the "D" brackets and is tied into the axel brackets on the other side of the 3ph arms with swivel balls on both ends. I don't have a great photo of it -but if there is interest I can get one.


For using a gooseneck on the road I have a hitch that mounts in the bracket for the toplink of the 3ph with two pins- also designed by Uniquip. I can get a photo of this if there is interest too.


Off topic, but maybe of interest too for versatility- I am almost finished with the bob-cat quick-tach brackets for the loader-
 

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Discussion Starter #9
I don't have a great photo of it -but if there is interest I can get one.

The more pics, the better. It looks like I'm gonna need to have that 3-point hitch tow bar fabricated until I can afford a trailer that fits the rockinger. Any pics are gonna be really helpful in the design.
 

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Mogish,
I would suggest getting a frame fabricated, either mounting to the two link arm ends and direct to the top link mounting on the mog, ie triangulated, but therefore not height adjustable, or use an upright "A" frame with a top link, to prevent the 50mm ball rotating. It could be considered prudent to use two bolts with "nylock" nuts rather than linch pins in the ends, for additional security.
The farming community in UK and Europe used to use a " nine hole bar" between the link arm ends, the trailer or implement having a clevis hitch, so the pull/push was centred on the nine hole bar, if this bar is used rotationally unrestrained, the risk is that when the ball rotates, it is possibly enough to spring off depending on hitch construction / amount of wear.
The 50mm ball hitch is afaik rated for up to 4500 kg, though linked / air brakes being needed for this classification, our overrun brakes only being good for 3500kg
cheers
M
 

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U1250L DOKA
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Hi Mogish,
Here is what I use around the farm or between fields if the load isn't too big


For pulling heavier loads (often 12ton dump trailer) I have a swinging drawbar made by Uniquip - it hangs on the "D" brackets and is tied into the axel brackets on the other side of the 3ph arms with swivel balls on both ends. I don't have a great photo of it -but if there is interest I can get one.


For using a gooseneck on the road I have a hitch that mounts in the bracket for the toplink of the 3ph with two pins- also designed by Uniquip. I can get a photo of this if there is interest too.


Off topic, but maybe of interest too for versatility- I am almost finished with the bob-cat quick-tach brackets for the loader-
More photos would be great. I am trying to come up with a hitch arangement to haul a dump box behind my mog and any info would be welcome.
 

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Hi Lyrch,
Here are some more photos - pardon the grime, I have a leaky quick connect on one circuit.

the hooks on the drawbar frame are for setting depth on the 3ph - a 3/8" chain hitches from lower arm and over the hook on each side. To set the depth I just let the 3ph float down to where the chain takes up the slack.
In the following picture you can see how the drawbar ties into the axle brackets.

I also took a picture of the gooseneck attachment that fits in the top link bracket of the 3ph - I have the hydraulic top link fitted right now, so I did not take a picture installed, but you can get the general idea.

I don't know if you can get these from Uniquip still, but it might be worth a call.
 
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